Nikolas Sargeant
TL;DR
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Kalshi has reportedly signed an exclusive prediction market partnership with the U.S. Tennis Association for the US Open.
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The agreement took effect immediately, although it was reportedly finalized only after the tournament’s qualifying rounds.
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The USTA is said to be blocking rival prediction platforms from advertising at the venue and across ESPN’s tournament coverage.
Kalshi Secures Exclusive US Open Partnership
Kalshi has reportedly signed an exclusive agreement with the U.S. Tennis Association to become the official prediction market platform partner of the US Open.
The partnership took effect as the tournament’s main draw began Sunday in Flushing Meadows, New York, according to Front Office Sports, which cited two people familiar with the agreement.
Financial terms were not disclosed. The deal was reportedly not finalized until after the tournament’s qualifying rounds concluded last week.
The US Open is owned and operated by the USTA, which had initially planned to explore prediction market partnerships for 2027 and beyond. However, newly appointed USTA CEO Craig Tiley reportedly played a major role in accelerating negotiations and securing an agreement for the 2026 tournament.
Tiley assumed the position on July 20. One of the agreement’s most unusual provisions reportedly gives Kalshi extensive advertising exclusivity.
According to one source cited by Front Office Sports, the USTA is preventing competing prediction market platforms from advertising at the US Open venue or during television coverage of the tournament. The restriction reportedly extends to ESPN’s broadcasts.
Such broad exclusivity could give Kalshi significant visibility while limiting the ability of competitors such as Polymarket to reach tennis audiences during one of the sport’s biggest events.
However, Kalshi was not listed among the US Open’s official partners as of Sunday afternoon.
A Kalshi blog post published earlier that day, which examined the odds for the women’s singles tournament, also included a disclaimer stating that the company was not affiliated with the US Open or the Women’s Tennis Association.
The apparent discrepancies may reflect how recently the agreement was completed.
Kalshi declined to comment to Front Office Sports, while representatives for the USTA and ESPN did not immediately respond. The company also did not immediately answer a separate request for comment from The Block.
Prediction Markets Deepen Ties with Major Sports Organizations
The reported US Open agreement is the latest indication that prediction market platforms are becoming increasingly involved in professional sports.
Kalshi and Polymarket are both official partners of the National Hockey League. Polymarket has also reached agreements with Major League Baseball and the New York Yankees.
Kalshi, meanwhile, has announced partnerships with several MLB teams, including the Atlanta Braves, Boston Red Sox, Los Angeles Dodgers, San Diego Padres, and San Francisco Giants.
Newer companies are also entering the sector. Novig recently partnered with the New York Mets, becoming the first prediction market platform to secure a deal with an individual MLB team.
These agreements allow prediction platforms to promote markets tied to game outcomes and other sporting events while increasing their visibility among mainstream audiences.
Sports have become a central component of the prediction market industry’s rapid growth.
Kalshi, Polymarket, and Polymarket US generated a combined $41.2 billion in trading volume so far in August, according to The Block’s data dashboard. Kalshi represented approximately $33.7 billion of that total, equivalent to nearly 82% of the combined volume.
Sports-event contracts continue to account for a significant share of activity on Kalshi. The platform has also experienced growing demand for combination and parlay-style products known as “Exotics.”
Although some of those products appear under The Block’s “Other” category, most are reportedly linked to sports outcomes.
The US Open partnership could further increase activity by connecting Kalshi with a major international sporting event and giving the platform exclusive access to tournament advertising opportunities.
